Chlorine
Chlorine is in the halogen group and it is the second lightest element in that group. This element was discovered by Carl Wihelm Scheele,a Swedish Pomeranian pharmaceutical chemist. Chlorine's compound is sodium chloride.
Symbol: Cl
Atomic Number:17
Atomic Weight: 35.453
Colour: Green
Standard State: Gas at 25 °C
Classification: Non-metallic
When Carl Wihelm Scheele discovered chlorine in 1774, he failed to establish chlorine as an element. In 1810, Sir Humphry Davy named chlorine an element because chlorine can react to other elements.
Density: 2898g/l
Melting Point: -101.5 °C
Boiling Point: -34.04 °C
Chlorine is a dangerous toxic gas and can be turn into a very dangerous chemical weapon which was a big part of chemical warfare. Lots of countries during world war one used gas with deadly chlorine gas in it. Chlorine has been used in tear gas and lethal gas.
Chlorine kills bacteria so today, lots of people used chlorine in pools to make the water safe for people to swim.
Chlorine has been used to keep our water safe from diseases such as cholera and typhoid fever
However, chlorine has been used as an un-environmentally friendly pesticide called DDT(dichlorodiphenyltrichloroethane) which almost caused the extinction of the peregrine flacon.